This invention relates to newly identified polynucleotides, polypeptides encoded by such polynucleotides, the use of such polynucleotides and polypeptides, as well as the production of such polynucleotides and polypeptides. The polypeptide of the present invention has been putatively identified as the human homolog of the mouse Extracellular Matrix-1 protein, sometimes hereinafter referred to as xe2x80x9chECM-1.xe2x80x9d The invention also relates to inhibiting the action of such polypeptides.
The process of embryonic bone formation involves the creation of an extracellular matrix that mineralizes during the course of tissue maturation. This matrix is subject to constant remodeling during the lifetime of an individual, through the combined actions of osteoblasts and osteoclasts. A careful balance of matrix formation and resorption must be maintained because perturbations can result in various bone disorders.
The extracellular matrix of bone consists of two phases, an organic phase and a mineral phase. The organic phase consists primarily of the collagen type I fibrils that are associated with a number of noncollagenous matrix proteins. Interest in the noncollagenous proteins of the bone has been greatly stimulated since Urist first demonstrated that demineralized bone extracts could induce ectopic bone formation (Urist, M. R., Science, 150:893-899 (1965)). Noncollagenous proteins of bone are now believed to be involved in mineralization as well as the local regulation of bone cell function (Heinegard, D. and Oldberg, A., Connective Tissue and Its Heritable Disorders (Royce, P. M. and Steinmann, B., EDS), pages 189-209, Wiley-Liss, New York (1993), and Von der Mark, K. and Goodman, S., id.). In the past few years, a number of noncollagenous proteins of bone have been isolated and characterized; among these are osteocalcin, osteopontin, osteonectin and bone sialoprotein (Heinegard, D. and Oldberg, A., FASEB J., 3:2042-2051 (1985)).
A clonal osteogenic cell line (MN7) from bone marrow stroma of the adult mouse has been established (Mathieu, E., et al., Calcif. Tissue Int., 50:362-371 (1992)). These cells, under appropriate conditions, undergo typical osteoblastic differentiation in vitro and are able to form a mineralized extracellular matrix (Mathieu, E. and Merregaert, J., J. Bone Miner. Res., 9:183-192 (1994)).
A cDNA coding for a novel secretory protein of mouse (p85), has been cloned, characterized and genetically mapped (Bhalerao, J., et al., J. Biol. Chem., 270 (27):16385-16394 (1995)). The full-length cDNA contains an open reading frame of 1677 bp encoding a protein of 559 amino acids. The clone contains a hydrophobic signal peptide characteristic of a secreted protein. The message of 1.9 kb is expressed in various tissues, such as liver, heart, lungs, etc., whereas a splice variant was present in embryonic cartilage in skin. This gene p85, called Ecm1 for extracellular matrix protein 1, maps on chromosome 3 of mouse in a region containing several loci involved in skin development disorders.
The polypeptide of the present invention has highest amino acid sequence homology to growth factor Ecm1.
In accordance with one aspect of the present invention, there is provided a novel mature polypeptide, as well as biologically active and diagnostically or therapeutically useful fragments, analogs and derivatives thereof. The polypeptide of the present invention is of human origin.
In accordance with another aspect of the present invention, there are provided isolated nucleic acid molecules encoding a polypeptide of the present invention including mRNAs, cDNAs, genomic DNAs as well as analogs and biologically active and diagnostically or therapeutically useful fragments thereof.
In accordance with another aspect of the present invention there is provided an isolated nucleic acid molecule encoding a mature polypeptide expressed by the DNA contained in ATCC Deposit No. 97302.
In accordance with yet a further aspect of the present invention, there is provided a process for producing such polypeptide by recombinant techniques comprising culturing recombinant prokaryotic and/or eukaryotic host cells, containing a nucleic acid sequence encoding a polypeptide of the present invention, under conditions promoting expression of said protein and subsequent recovery of said protein.
In accordance with yet a further aspect of the present invention, there is provided a process for utilizing such polypeptide, or polynucleotide encoding such polypeptide for therapeutic purposes, for example, to stimulate osteoblast and osteoclast differentiation and growth, which may be utilized to treat bone disorders and promote bone formation for healing of bone fractures and treatment of osteoporosis and osteogenesis imperfecta, and to stimulate angiogenesis, which may be utilized to revascularize injured tissue.
In accordance with yet a further aspect of the present invention, there are provided antibodies against such polypeptides.
In accordance with another aspect of the present invention, there are provided hECM-1 agonists which mimic hECM-1 and bind to the hECM-1 receptors and antagonists against such polypeptides, which may be used to inhibit the action of such polypeptides. The agonists may be employed to treat disease conditions related to an underexpression of the ECM-1 polypeptide and the antagonists may be employed to treat disease conditions related to an overexpression of such polypeptide. Such disease conditions include, for example, osteodystrophy, osteohypertrophy, osteoma, osteopetrusis, osteoporosis, osteoblastoma, and cancer.
In accordance with yet a further aspect of the present invention, there is also provided nucleic acid probes comprising nucleic acid molecules of sufficient length to specifically hybridize to a nucleic acid sequence of the present invention.
In accordance with still another aspect of the present invention, there are provided diagnostic assays for detecting diseases or susceptibility to diseases related to mutations in the nucleic acid sequences encoding a polypeptide of the present invention.
In accordance with yet a further aspect of the present invention, there is provided a process for utilizing such polypeptides, or polynucleotides encoding such polypeptides, for in vitro purposes related to scientific research, for example, synthesis of DNA and manufacture of DNA vectors.
These and other aspects of the present invention should be apparent to those skilled in the art from the teachings herein.